The present invention relates generally to apparatus and methods for the wet processing of textile articles and, more particularly, to apparatus and methods for washing textile articles, e.g., before or after a dyeing operation.
It has been commonplace for centuries to subject textile articles to various wet processing treatments at varying stages of textile manufacturing operations. As one example, the vast majority of textile articles are dyed at some stage of their overall processing to impart coloration for aesthetic and style reasons. The types of apparatus and processes used for textile dyeing are numerous and diverse. Likewise, the dyes used for such operations are equally varied. Ancillary processes are also commonly carried out on textile articles before and/or after dyeing, e.g., textile articles may be subjected to a washing operation before dyeing to prepare the textile articles to receive dye and, likewise, textile articles may be washed after dyeing to remove excess dye.
Despite many modern advances in textile chemistry and, particularly, in the development of synthetic dyes and dyeing processes, many textile articles continue to be dyed using natural dyes applied by techniques which have been known and used for centuries. One particular example is the use of plant-derived indigo dyes used in the production of cotton-based denim fabrics. Due largely to the increasing popularity of wearing apparel made of denim, particularly so-called blue jeans, the use of indigo dyes continues to rise despite the relatively primitive nature of the dye and inefficiencies and environmental concerns with its use.
Indigo dyeing is predominantly performed on textile yarns, e.g., in the form of a traveling rope assembled of multiple individual yarns or in a traveling open sheet of side-by-side yarns, prior to their incorporation into denim fabric. Basically, the dyeing process requires the yarn rope or sheet to be passed into and out of multiple dip baths to progressively build penetration of the dye into the constituent yarns. Preparatory to dyeing, the yarns may be washed to remove impurities such as natural oils, waxes, and foreign matter which typically are found in natural cotton fibers. Likewise, after the yarn rope or sheet has undergone a sufficient number of dippings to achieve a desired dye shade, the yarns must then be washed through a series of water rinse baths to remove excess dye which remains on the yarn surfaces without having penetrated into the yarns.
Although machinery has been developed to automate these operations, this basic process of indigo dyeing has remained largely unchanged. Overall, the process presents many environmental concerns due to the substantial volumes of water which must be utilized for the numerous dip baths and for pre-dyeing and post-dyeing washings and, in turn, the substantial volumes of dye solution and dirty wash water which must be cleaned. In recent years, considerable effort has been devoted to developing advanced techniques for rehabilitating dye solutions and dirty wash water, but little effort has been successfully devoted to reducing the amount of water used in the first place.
Accordingly, a need exists within the textile industry for improved apparatus and processes used in the wet processing of textile articles, particular in association with textile dyeing operations, by which the amount of clean water devoted to the such wet processing operations can be reduced thereby lessening the required clean-up and attendant environmental impact.